Contactless Power Reception Temperature Estimation via Coil Shift
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Solution Overview
Problem
Contactless power reception devices face temperature increases due to power loss, which existing temperature estimation methods fail to accurately monitor without installing temperature sensors, leading to increased device size and cost.
Innovation Solution
A temperature estimation device and method that acquires power loss of the power transmission coil and estimates the ambient temperature of the power reception coil based on preset heat generation and positional shifts between coils, adjusting for the impact of power loss and positional changes without requiring a temperature sensor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a temperature sensor is installed to monitor the temperature of the power reception device, then the temperature monitoring accuracy is improved, but the device scale and cost increase
Solution Approach 1:
The patent replaces the physical temperature sensor (mechanical/thermal measurement system) with an electromagnetic-based calculation system. The temperature estimation unit calculates temperature based on power loss data from the power transmission coil and heat generation characteristics, substituting direct thermal measurement with indirect electromagnetic field-based computation.
Solution Approach 2:
The patent introduces power loss as an intermediary parameter to indirectly measure temperature. Instead of directly measuring temperature with a sensor, the system measures power loss in the power transmission coil and uses this intermediate data to calculate the temperature of the power reception device through established thermal models.
2Measurement precision
If a temperature sensor is installed to monitor the temperature of the power reception device, then the temperature monitoring accuracy is improved, but the cost increases
Solution Approach 1:
The patent uses inexpensive computational resources and existing sensor data (power loss measurements) to estimate temperature, replacing expensive temperature sensors. The calculation-based approach uses readily available electrical parameters and standard thermal models, significantly reducing component costs while maintaining adequate temperature monitoring capability.
Solution Approach 2:
The patent replaces expensive thermal measurement hardware with computational algorithms that process electrical parameters. The temperature estimation unit uses power loss data and heat generation models to calculate temperature, eliminating the need for costly temperature sensing components.
3Adaptability or versatility
If the positional relationship between coils is shifted from normal position, then the power transmission adaptability is improved, but the temperature rise due to power loss increases
Solution Approach 1:
The patent implements a feedback mechanism where the temperature estimation unit continuously monitors calculated temperature based on power loss measurements. When positional shifts cause increased power loss and temperature rise, the system can detect this through the temperature estimation and provide feedback to adjust power transmission parameters or alert operators to proper positioning.
Solution Approach 2:
The patent performs preliminary temperature estimation based on power loss calculations before excessive heating occurs. By continuously estimating temperature from power loss data, the system can predict temperature trends resulting from positional shifts and take preventive actions before dangerous temperature levels are reached.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Accurately estimates ambient temperature of the power reception coil, preventing excessive temperature rises and reducing device complexity and cost by eliminating the need for temperature sensors, while controlling power transmission to maintain safe operating temperatures.
Implementation Method 1
a contactless power supply system that contactlessly supplies power to charge a battery mounted on an electric vehicle. In the contactless power supply system, power is transmitted via a power transmission coil from a power transmission device provided on the ground side and the transmitted power is received by a power reception coil
Implementation Method 2
when a change in the gap between the power transmission coil and the power reception coil or a planar positional shift between the power transmission coil and the power reception coil occurs, the power loss of the power transmission coil increases and the temperature of the power reception device rises due to an increase of this power loss
Data Source
AI summary
A charging controller (25) acquires the power loss of a power transmission coil (31) from a power supply device (100) via wireless communication. A temperature estimation unit (33) estimates the ambient temperature of a power reception coil on the basis of a preset amount of heat generation of a power reception device (200) and the power loss of the power transmission coil (31). In this case, when the positional relationship between the power transmission coil (31) and the power reception coil (41) is shifted from a normal positional relationship, the temperature estimation unit (33) increases, in accordance with the magnitude of positional shift amount, the contribution to a temperature rise due to the power loss of the power transmission coil (31). Accordingly, an abnormal increase in the ambient temperature of the power reception coil (41) can be prevented.